The present invention generally relates to the field of engine fuels. More specifically, the present invention relates to a composition of blended engine fuel made from petroleum diesel fuel in minor part combined with waste vegetable or animal oils in major part, and further modified with an admixture of stabilizing chemical agents. The resultant hybrid fuel is particularly suitable for applications powered by diesel engines, but is additionally useful for other fueling and heating applications. The invention is further suitable as an internal mechanical lubricant. The present invention also pertains to the obligatory method for producing this hybrid fuel.